3 onion ; thinly sliced
1/4 pound feta cheese ; crumbled
1/4 cup olive oil
2 tablespoon wine vinegar
2 tablespoon lemon juice
1/2 teaspoon oregano
salt and pepper
1 teaspoon sugar ; or to taste

Mix cheese and onions together in a bowl. Combine remaining ingredients and pour over the onions. Allow to marinate covered in the refrigerator for several hours.